The Collaborative International Dictionary of English v.0.48:
On \On\ ([o^]n), prep. [OE. on, an, o, a, AS. on, an; akin to D.
aan, OS. & G. an, OHG. ana, Icel. [=a], Sw. [*a], Goth. ana,
Russ. na, L. an-, in anhelare to pant, Gr. 'ana`, Zend ana.
[root]195. Cf. A-, 1, Ana-, Anon.]
The general signification of on is situation, motion, or
condition with respect to contact or support beneath; as:
1. At, or in contact with, the surface or upper part of a
thing, and supported by it; placed or lying in contact
with the surface; as, the book lies on the table, which
stands on the floor of a house on an island.
I stood on the bridge at midnight. --Longfellow.
2. To or against the surface of; -- used to indicate the
motion of a thing as coming or falling to the surface of
another; as, rain falls on the earth.
Whosoever shall fall on this stone shall be broken.
3. Denoting performance or action by contact with the
surface, upper part, or outside of anything; hence, by
means of; with; as, to play on a violin or piano. Hence,
figuratively, to work on one's feelings; to make an
impression on the mind.
4. At or near; adjacent to; -- indicating situation, place,
or position; as, on the one hand, on the other hand; the
fleet is on the American coast.
5. In addition to; besides; -- indicating multiplication or
succession in a series; as, heaps on heaps; mischief on
mischief; loss on loss; thought on thought. --Shak.
6. Indicating dependence or reliance; with confidence in; as,
to depend on a person for assistance; to rely on; hence,
indicating the ground or support of anything; as, he will
promise on certain conditions; to bet on a horse; based on
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7. At or in the time of; during; as, on Sunday we abstain
from labor. See At (synonym).
8. At the time of; -- often conveying some notion of cause or
motive; as, on public occasions, the officers appear in
full dress or uniform; the shop is closed on Sundays.
Hence, in consequence of, or following; as, on the
ratification of the treaty, the armies were disbanded;
start on the count of three.
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9. Toward; for; -- indicating the object of some passion; as,
have pity or compassion on him.
10. At the peril of, or for the safety of. "Hence, on thy
11. By virtue of; with the pledge of; -- denoting a pledge or
engagement, and put before the thing pledged; as, he
affirmed or promised on his word, or on his honor.
12. To the account of; -- denoting imprecation or invocation,
or coming to, falling, or resting upon; as, on us be all
the blame; a curse on him.
His blood be on us and on our children. --Matt.
13. In reference or relation to; as, on our part expect
punctuality; a satire on society.
14. Of. [Obs.] "Be not jealous on me." --Shak.
Or have we eaten on the insane root
That takes the reason prisoner? --Shak.
Note: Instances of this usage are common in our older
writers, and are sometimes now heard in illiterate
15. Occupied with; in the performance of; as, only three
officers are on duty; on a journey; on the job; on an
assignment; on a case; on the alert.
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16. In the service of; connected with; a member of; as, he is
on a newspaper; on a committee.
Note: On and upon are in general interchangeable. In some
applications upon is more euphonious, and is therefore
to be preferred; but in most cases on is preferable.
17. In reference to; about; concerning; as, to think on it;
to meditate on it.
On a bowline. (Naut.) Same as Closehauled.
On a wind, or On the wind (Naut.), sailing closehauled.
On a sudden. See under Sudden.
On board, On draught, On fire, etc. See under Board,
Draught, Fire, etc.
On it, On't, of it. [Obs. or Colloq.] --Shak.
On shore, on land; to the shore.
On the road, On the way, On the wing, etc. See under
Road, Way, etc.
On to, upon; on; to; -- sometimes written as one word,
onto, and usually called a colloquialism; but it may be
regarded in analogy with into.
They have added the -en plural form on to an elder
We see the strength of the new movement in the new
class of ecclesiastics whom it forced on to the
stage. --J. R. Green.